1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
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  23  */
  24 
  25 #ifndef SHARE_RUNTIME_MUTEXLOCKER_HPP
  26 #define SHARE_RUNTIME_MUTEXLOCKER_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/flags/flagSetting.hpp"
  30 #include "runtime/mutex.hpp"
  31 
  32 // Mutexes used in the VM.
  33 
  34 extern Mutex*   Patching_lock;                   // a lock used to guard code patching of compiled code
  35 extern Monitor* SystemDictionary_lock;           // a lock on the system dictionary
  36 extern Mutex*   ProtectionDomainSet_lock;        // a lock on the pd_set list in the system dictionary
  37 extern Mutex*   SharedDictionary_lock;           // a lock on the CDS shared dictionary
  38 extern Mutex*   Module_lock;                     // a lock on module and package related data structures
  39 extern Mutex*   CompiledIC_lock;                 // a lock used to guard compiled IC patching and access
  40 extern Mutex*   InlineCacheBuffer_lock;          // a lock used to guard the InlineCacheBuffer
  41 extern Mutex*   VMStatistic_lock;                // a lock used to guard statistics count increment
  42 extern Mutex*   JNIGlobalAlloc_lock;             // JNI global storage allocate list lock
  43 extern Mutex*   JNIGlobalActive_lock;            // JNI global storage active list lock
  44 extern Mutex*   JNIWeakAlloc_lock;               // JNI weak storage allocate list lock
  45 extern Mutex*   JNIWeakActive_lock;              // JNI weak storage active list lock
  46 extern Mutex*   StringTableWeakAlloc_lock;       // StringTable weak storage allocate list lock
  47 extern Mutex*   StringTableWeakActive_lock;      // STringTable weak storage active list lock
  48 extern Mutex*   JNIHandleBlockFreeList_lock;     // a lock on the JNI handle block free list
  49 extern Mutex*   VMWeakAlloc_lock;                // VM Weak Handles storage allocate list lock
  50 extern Mutex*   VMWeakActive_lock;               // VM Weak Handles storage active list lock
  51 extern Mutex*   ResolvedMethodTable_lock;        // a lock on the ResolvedMethodTable updates
  52 extern Mutex*   JmethodIdCreation_lock;          // a lock on creating JNI method identifiers
  53 extern Mutex*   JfieldIdCreation_lock;           // a lock on creating JNI static field identifiers
  54 extern Monitor* JNICritical_lock;                // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
  55 extern Mutex*   JvmtiThreadState_lock;           // a lock on modification of JVMTI thread data
  56 extern Monitor* Heap_lock;                       // a lock on the heap
  57 extern Mutex*   ExpandHeap_lock;                 // a lock on expanding the heap
  58 extern Mutex*   AdapterHandlerLibrary_lock;      // a lock on the AdapterHandlerLibrary
  59 extern Mutex*   SignatureHandlerLibrary_lock;    // a lock on the SignatureHandlerLibrary
  60 extern Mutex*   VtableStubs_lock;                // a lock on the VtableStubs
  61 extern Mutex*   SymbolArena_lock;                // a lock on the symbol table arena
  62 extern Monitor* StringDedupQueue_lock;           // a lock on the string deduplication queue
  63 extern Mutex*   StringDedupTable_lock;           // a lock on the string deduplication table
  64 extern Monitor* CodeCache_lock;                  // a lock on the CodeCache, rank is special, use MutexLockerEx
  65 extern Mutex*   MethodData_lock;                 // a lock on installation of method data
  66 extern Mutex*   TouchedMethodLog_lock;           // a lock on allocation of LogExecutedMethods info
  67 extern Mutex*   RetData_lock;                    // a lock on installation of RetData inside method data
  68 extern Mutex*   DerivedPointerTableGC_lock;      // a lock to protect the derived pointer table
  69 extern Monitor* CGCPhaseManager_lock;            // a lock to protect a concurrent GC's phase management
  70 extern Monitor* VMOperationQueue_lock;           // a lock on queue of vm_operations waiting to execute
  71 extern Monitor* VMOperationRequest_lock;         // a lock on Threads waiting for a vm_operation to terminate
  72 extern Monitor* Threads_lock;                    // a lock on the Threads table of active Java threads
  73                                                  // (also used by Safepoints too to block threads creation/destruction)
  74 extern Mutex*   NonJavaThreadsList_lock;         // a lock on the NonJavaThreads list
  75 extern Mutex*   NonJavaThreadsListSync_lock;     // a lock for NonJavaThreads list synchronization
  76 extern Monitor* CGC_lock;                        // used for coordination between
  77                                                  // fore- & background GC threads.
  78 extern Monitor* STS_lock;                        // used for joining/leaving SuspendibleThreadSet.
  79 extern Monitor* FullGCCount_lock;                // in support of "concurrent" full gc
  80 extern Monitor* SATB_Q_CBL_mon;                  // Protects SATB Q
  81                                                  // completed buffer queue.
  82 extern Monitor* DirtyCardQ_CBL_mon;              // Protects dirty card Q
  83                                                  // completed buffer queue.
  84 extern Mutex*   Shared_DirtyCardQ_lock;          // Lock protecting dirty card
  85                                                  // queue shared by
  86                                                  // non-Java threads.
  87 extern Mutex*   MarkStackFreeList_lock;          // Protects access to the global mark stack free list.
  88 extern Mutex*   MarkStackChunkList_lock;         // Protects access to the global mark stack chunk list.
  89 extern Mutex*   MonitoringSupport_lock;          // Protects updates to the serviceability memory pools.
  90 extern Mutex*   ParGCRareEvent_lock;             // Synchronizes various (rare) parallel GC ops.
  91 extern Mutex*   Compile_lock;                    // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
  92 extern Monitor* MethodCompileQueue_lock;         // a lock held when method compilations are enqueued, dequeued
  93 extern Monitor* CompileThread_lock;              // a lock held by compile threads during compilation system initialization
  94 extern Monitor* Compilation_lock;                // a lock used to pause compilation
  95 extern Mutex*   CompileTaskAlloc_lock;           // a lock held when CompileTasks are allocated
  96 extern Mutex*   CompileStatistics_lock;          // a lock held when updating compilation statistics
  97 extern Mutex*   DirectivesStack_lock;            // a lock held when mutating the dirstack and ref counting directives
  98 extern Mutex*   MultiArray_lock;                 // a lock used to guard allocation of multi-dim arrays
  99 extern Monitor* Terminator_lock;                 // a lock used to guard termination of the vm
 100 extern Monitor* InitCompleted_lock;              // a lock used to signal threads waiting on init completed
 101 extern Monitor* BeforeExit_lock;                 // a lock used to guard cleanups and shutdown hooks
 102 extern Monitor* Notify_lock;                     // a lock used to synchronize the start-up of the vm
 103 extern Mutex*   ProfilePrint_lock;               // a lock used to serialize the printing of profiles
 104 extern Mutex*   ExceptionCache_lock;             // a lock used to synchronize exception cache updates
 105 extern Mutex*   OsrList_lock;                    // a lock used to serialize access to OSR queues
 106 extern Mutex*   NMethodSweeperStats_lock;        // a lock used to serialize access to sweeper statistics
 107 
 108 #ifndef PRODUCT
 109 extern Mutex*   FullGCALot_lock;                 // a lock to make FullGCALot MT safe
 110 #endif // PRODUCT
 111 extern Mutex*   Debug1_lock;                     // A bunch of pre-allocated locks that can be used for tracing
 112 extern Mutex*   Debug2_lock;                     // down synchronization related bugs!
 113 extern Mutex*   Debug3_lock;
 114 
 115 extern Mutex*   RawMonitor_lock;
 116 extern Mutex*   PerfDataMemAlloc_lock;           // a lock on the allocator for PerfData memory for performance data
 117 extern Mutex*   PerfDataManager_lock;            // a long on access to PerfDataManager resources
 118 extern Mutex*   ParkerFreeList_lock;
 119 extern Mutex*   OopMapCacheAlloc_lock;           // protects allocation of oop_map caches
 120 
 121 extern Mutex*   FreeList_lock;                   // protects the free region list during safepoints
 122 extern Mutex*   OldSets_lock;                    // protects the old region sets
 123 extern Monitor* RootRegionScan_lock;             // used to notify that the CM threads have finished scanning the IM snapshot regions
 124 
 125 extern Mutex*   Management_lock;                 // a lock used to serialize JVM management
 126 extern Monitor* Service_lock;                    // a lock used for service thread operation
 127 extern Monitor* PeriodicTask_lock;               // protects the periodic task structure
 128 extern Monitor* RedefineClasses_lock;            // locks classes from parallel redefinition
 129 extern Monitor* ThreadsSMRDelete_lock;           // Used by ThreadsSMRSupport to take pressure off the Threads_lock
 130 extern Mutex*   SharedDecoder_lock;              // serializes access to the decoder during normal (not error reporting) use
 131 extern Mutex*   DCmdFactory_lock;                // serialize access to DCmdFactory information
 132 #if INCLUDE_NMT
 133 extern Mutex*   NMTQuery_lock;                   // serialize NMT Dcmd queries
 134 #endif
 135 #if INCLUDE_CDS && INCLUDE_JVMTI
 136 extern Mutex*   CDSClassFileStream_lock;         // FileMapInfo::open_stream_for_jvmti
 137 #endif
 138 #if INCLUDE_JFR
 139 extern Mutex*   JfrStacktrace_lock;              // used to guard access to the JFR stacktrace table
 140 extern Monitor* JfrMsg_lock;                     // protects JFR messaging
 141 extern Mutex*   JfrBuffer_lock;                  // protects JFR buffer operations
 142 extern Mutex*   JfrStream_lock;                  // protects JFR stream access
 143 extern Monitor* JfrThreadSampler_lock;           // used to suspend/resume JFR thread sampler
 144 #endif
 145 
 146 #ifndef SUPPORTS_NATIVE_CX8
 147 extern Mutex*   UnsafeJlong_lock;                // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
 148 #endif
 149 
 150 extern Mutex*   MetaspaceExpand_lock;            // protects Metaspace virtualspace and chunk expansions
 151 extern Mutex*   ClassLoaderDataGraph_lock;       // protects CLDG list, needed for concurrent unloading
 152 
 153 
 154 extern Monitor* CodeHeapStateAnalytics_lock;     // lock print functions against concurrent analyze functions.
 155                                                  // Only used locally in PrintCodeCacheLayout processing.
 156 
 157 // A MutexLocker provides mutual exclusion with respect to a given mutex
 158 // for the scope which contains the locker.  The lock is an OS lock, not
 159 // an object lock, and the two do not interoperate.  Do not use Mutex-based
 160 // locks to lock on Java objects, because they will not be respected if a
 161 // that object is locked using the Java locking mechanism.
 162 //
 163 //                NOTE WELL!!
 164 //
 165 // See orderAccess.hpp.  We assume throughout the VM that MutexLocker's
 166 // and friends constructors do a fence, a lock and an acquire *in that
 167 // order*.  And that their destructors do a release and unlock, in *that*
 168 // order.  If their implementations change such that these assumptions
 169 // are violated, a whole lot of code will break.
 170 
 171 // Print all mutexes/monitors that are currently owned by a thread; called
 172 // by fatal error handler.
 173 void print_owned_locks_on_error(outputStream* st);
 174 
 175 char *lock_name(Mutex *mutex);
 176 
 177 class MutexLocker: StackObj {
 178  private:
 179   Monitor * _mutex;
 180  public:
 181   MutexLocker(Monitor * mutex) {
 182     assert(mutex->rank() != Mutex::special,
 183       "Special ranked mutex should only use MutexLockerEx");
 184     _mutex = mutex;
 185     _mutex->lock();
 186   }
 187 
 188   // Overloaded constructor passing current thread
 189   MutexLocker(Monitor * mutex, Thread *thread) {
 190     assert(mutex->rank() != Mutex::special,
 191       "Special ranked mutex should only use MutexLockerEx");
 192     _mutex = mutex;
 193     _mutex->lock(thread);
 194   }
 195 
 196   ~MutexLocker() {
 197     _mutex->unlock();
 198   }
 199 
 200 };
 201 
 202 // for debugging: check that we're already owning this lock (or are at a safepoint)
 203 #ifdef ASSERT
 204 void assert_locked_or_safepoint(const Monitor * lock);
 205 void assert_locked_or_safepoint_weak(const Monitor * lock);
 206 void assert_lock_strong(const Monitor * lock);
 207 #else
 208 #define assert_locked_or_safepoint(lock)
 209 #define assert_locked_or_safepoint_weak(lock)
 210 #define assert_lock_strong(lock)
 211 #endif
 212 
 213 // A MutexLockerEx behaves like a MutexLocker when its constructor is
 214 // called with a Mutex.  Unlike a MutexLocker, its constructor can also be
 215 // called with NULL, in which case the MutexLockerEx is a no-op.  There
 216 // is also a corresponding MutexUnlockerEx.  We want to keep the
 217 // basic MutexLocker as fast as possible.  MutexLockerEx can also lock
 218 // without safepoint check.
 219 
 220 class MutexLockerEx: public StackObj {
 221  private:
 222   Monitor * _mutex;
 223  public:
 224   MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
 225     _mutex = mutex;
 226     if (_mutex != NULL) {
 227       assert(mutex->rank() > Mutex::special || no_safepoint_check,
 228         "Mutexes with rank special or lower should not do safepoint checks");
 229       if (no_safepoint_check)
 230         _mutex->lock_without_safepoint_check();
 231       else
 232         _mutex->lock();
 233     }
 234   }
 235 
 236   ~MutexLockerEx() {
 237     if (_mutex != NULL) {
 238       _mutex->unlock();
 239     }
 240   }
 241 };
 242 
 243 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
 244 // a possibly null Monitor, and allows wait/notify as well which are
 245 // delegated to the underlying Monitor.
 246 
 247 class MonitorLockerEx: public MutexLockerEx {
 248  private:
 249   Monitor * _monitor;
 250  public:
 251   MonitorLockerEx(Monitor* monitor,
 252                   bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
 253     MutexLockerEx(monitor, no_safepoint_check),
 254     _monitor(monitor) {
 255     // Superclass constructor did locking
 256   }
 257 
 258   ~MonitorLockerEx() {
 259     #ifdef ASSERT
 260       if (_monitor != NULL) {
 261         assert_lock_strong(_monitor);
 262       }
 263     #endif  // ASSERT
 264     // Superclass destructor will do unlocking
 265   }
 266 
 267   bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
 268             long timeout = 0,
 269             bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
 270     if (_monitor != NULL) {
 271       return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
 272     }
 273     return false;
 274   }
 275 
 276   void notify_all() {
 277     if (_monitor != NULL) {
 278       _monitor->notify_all();
 279     }
 280   }
 281 
 282   void notify() {
 283     if (_monitor != NULL) {
 284       _monitor->notify();
 285     }
 286   }
 287 };
 288 
 289 
 290 
 291 // A GCMutexLocker is usually initialized with a mutex that is
 292 // automatically acquired in order to do GC.  The function that
 293 // synchronizes using a GCMutexLocker may be called both during and between
 294 // GC's.  Thus, it must acquire the mutex if GC is not in progress, but not
 295 // if GC is in progress (since the mutex is already held on its behalf.)
 296 
 297 class GCMutexLocker: public StackObj {
 298 private:
 299   Monitor * _mutex;
 300   bool _locked;
 301 public:
 302   GCMutexLocker(Monitor * mutex);
 303   ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
 304 };
 305 
 306 
 307 
 308 // A MutexUnlocker temporarily exits a previously
 309 // entered mutex for the scope which contains the unlocker.
 310 
 311 class MutexUnlocker: StackObj {
 312  private:
 313   Monitor * _mutex;
 314 
 315  public:
 316   MutexUnlocker(Monitor * mutex) {
 317     _mutex = mutex;
 318     _mutex->unlock();
 319   }
 320 
 321   ~MutexUnlocker() {
 322     _mutex->lock();
 323   }
 324 };
 325 
 326 // A MutexUnlockerEx temporarily exits a previously
 327 // entered mutex for the scope which contains the unlocker.
 328 
 329 class MutexUnlockerEx: StackObj {
 330  private:
 331   Monitor * _mutex;
 332   bool _no_safepoint_check;
 333 
 334  public:
 335   MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
 336     _mutex = mutex;
 337     _no_safepoint_check = no_safepoint_check;
 338     _mutex->unlock();
 339   }
 340 
 341   ~MutexUnlockerEx() {
 342     if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
 343       _mutex->lock_without_safepoint_check();
 344     } else {
 345       _mutex->lock();
 346     }
 347   }
 348 };
 349 
 350 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP